reproduction in plants

Reproduction in plants

What is reproduction? Reproduction is the process by which organisms produce produce more of their own kind.

Reproduction: The Continuity of Life

Reproduction

Sexual Reproduction

Asexual Reproduction

What is Sexual Reproduction?  Two  Two parents inoled inoled !sperm"pollen and egg as gametes# $rocess $rocess of mitosis and meiosis occurs. 

Sexual Reproduction A%&A'TA()S *+spring are genetically dierent and hae a better chance of suriing if conditions change. ,ygote can be protected by a thick coat. %-SA%&A'TA() 'eed to nd a mate to reproduce. reproduce. -s a longer process

What is Asexual Reproduction? *nly one parent is inoled. *+spring are genetically identical to their parent !they are all clones/made by mitosis only#. 

Asexual reproduction A%&A'TA() -t is a 0uicker process. *+spring are identical and hae adaptations of the parents. 'o need to nd a mate %-SA%&A'TA() *+spring are identical1 if conditions change1 all might not be suited.

Act 2.3.4 pg 56.

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 Terms  T erms Whorl/ circular pattern Regular/ parts of each whorl are identical. 

%icotyledonous =ower ontains > whorls androecium1 gynaecium1 calyx and corolla !calyx  corolla @ perianth# omplete =ower/ =ower/ has > whorls. $arts of each whorl in 3s or Bs 

Donocotyledonous Donocotyledon ous =ower ontains C whorls androecium1 gynaecium and perianth !$erianth '*T di+erentiated into corolla and calyx# $arts of each whorl in Cs 

$ollination  The transfer of pollen from the anther to the ripe stigma.

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Pollen Pollen

Selfpollination

Cross-pollination

Pollination Self-pollination •

Pollen from the anther is transferred to the stigma of the same flower/plant

Cross Pollination •

Pollen from the anther of one plant is transferred to the stigma of a different plant

Wind =owers

pollinated

• 8arge anthers • 'o petal •  8arge feathery stigma

Wind Pollinated Flowers

-nsect =owers

pollinated

• Small anthers • Eig colourfull petals • Small inside stigma • 'ectar as attraction

Insect Pollinated Flowers

Bird Pollinated Flowers 8ong tube/shaped =owers Eright red and yellow =owers 'o odour.

7ertilisation: The nucleus of the pollen  Foins with the nucleus of the the egg to form form a Gygote

After fertiliGation H    The seed deelops from from the oule and and fruit from from the oary. oary.

.

Seeds are dispersed and will germinate.

Signicance of seeds • Reduce competition when dispersed. • Surie harsh enironmental enironmental conditions while dormant. • Store food. • )nsure protection of the embryo. • $roide seedling with food until it can photosynthesise.

Seeds as sources of food: • • • • • •

7orm the staple diet of most people. an be used to make beerages. 7ruits are a source of itamins and minerals. 9sed to make spices spices.. *ther parts of plants also proide food Seeds are used as feed for animals.

$R)S)R&-'( )'%)D- S$)-)S -' S))% EA'JS

• South Africa has high endemism. • Seed banks can presere endangered1 endemic species and those with medicinal alue. •  The Dillenium Seed Eank $roFect $roFect was started in 3<<2 and they partnered partnered with SA'E-. • Seeds of the scarce1 endangered endangered and plants that hae medicinal alue are collected and kept in the seeds banks. • A %'A bank has been established in Jirstenbosch !W..#. %'A extracts are stored at /4< C     ̊